An imager making use of an electrophotographic imaging process comprises developer equipment for developing latent images on a photosensitive drum. For this developer, as shown typically in FIG. 20, there is a developer 201 known so far in the art, which is of the structure that comprises a hopper 202, a developing roller 203, a rotatable agitator 204 and a developing blade 205 (JP(A)2003-43812). With this developer 201, a toner 206 in the hopper 202 is fed by the agitator 204 to the developing roller 203 so that the toner in thin layer form is uniformly carried on the peripheral surface of the developing roller 203 by frictional electrification between the developing blade 205 and the developing roller 203. And then, the toner 206 passes from the developing roller 203 onto the photosensitive drum 207 with a latent image formed on it for development.
As shown typically in FIG. 21, the developing blade 205 known so far in the art is of the structure that comprises a rubber blade member 214 along the side edge 212A of a metallic support member 212 having a thickness of about 0.1 mm.
Now that the developing roller 203 rotates at a high speed (of 24 rpm or more for instance) so as to cope with faster operation of the electrophotographic imagers such as laser printers, however, problems with the prior art developing blade are that the resulting images are likely to be poor in density, and streak as well.